Minnesota edible forests

Dave, I have practically memorized Edible Forest Gardens, did one design out of it so far, it's my essential reference. So my question has to do with Minnesota, where the snow is still on the ground. We are going to have thoroughly unreliable weather. (I'm newly here and don't have my land yet, am messing around with a quarter acre right now.) I had thought the thing would be to bring in southern trees and shelter them until things got warmer, but now I see there will be sheltering to do all the way along, and maybe southern trees aren't such a good idea - but they'll have to handle summer heat and drought, spring/fall storms, and who knows what else.
What do you recommend on tree and shrub choices, in terms of reinterpreting the data in the book to match the uncertainty we're going to have? Oh yeah, do you think I'll be able to have my fig tree and my peach tree? In greenhouse only?
I'm thinking I'll need to have collapsible greenhouses, to protect things when needed and remove when it gets hot. Has anybody developed a model for this?
Last, just for fun - do you know anything to do with buckthorn except tear it up or get goats to attack it? (I learned permaculture from Peter Bane and Keith Johnson in southern Indiana, where they don't have the nasty stuff.)
Finally, a shameless plug for my two websites: http://vairochanafarm.wordpress.com/ and www.CompassionateEarthWalk.org.

Shodo,

Glad you find the books useful!

Figs in MN? I doubt it for a while, at least not without lots of work, but you can if you want. You could build a protective enclosure every winter--Eric Toensmeier has bananas in Holyoke Mass! He wraps it in hog fence, with plastic just inside the fence, leaves from the yard, Christmas lights to add a little heat, and I don't know what all else. It's a lot of work, but it works, and has for years.

High tunnels are quite useful and make a huge difference, even if they have no supplemental heat. I think they are going to be a valuable addition to the toolbox for most people in most climates. That's where figs and (semi-dwarf) peaches will be best for you, probably. But temp regulation is key: A friend of mine had a fig in a large pot that he and I took in and out of his basement for a few years until it got really big. So he put it in the ground and then built a tiny little greenhouse over it. That didn't work very well--it got too hot, the tree got confused and broke dormancy, and then it got killed in the cold temps at night.

A lot of this has to do with microclimate analysis and design, digging deep into the details of that, and the details of the plant physiology. Some southern plants will die back to the ground but resprout and make food the following year. Others can't hack that. Eric's Perennial Vegetables book list many species he calls "dieback perennials". Hardy enough in some cases. But the fig in the tiny greenhouse is a case in point--too small a greenhouse, got too hot too fast, shocked the plant with too wide a temp swing.

Generally I think we need to push the limits some, but obviously pushing them too much is a waste of effort. And, hell if I know, man! We're all trying to figure this out! Much to learn, much to learn.

As for buckthorn, it makes good biochar! But also: It coppices vigorously once it attains a certain (unknown) age--seedlings will not coppice. The bark of common buckthorn is rich in tannin and was used as a tanning agent. The wood is marble-like with close grains and reddish veins. It is used in woodwork and carpentry. In Russia it has been used for ornamental art wares and plywood. Common buckthorn wood is marketed in the United States because the yellow sapwood encircling rich orange heartwood has ornamental value. The hard wood of Dahurian buckthorn has also been used for making furniture, and oil has been extracted from the seeds for lubricating oil. It has been used for fencing and posts, turnery, tool handles. It has minor medicinal uses, its fruit is edible to a very limited degree ONLY in emergency, but use for over 10 days will cause significant potassium loss. NOTE: The berries are also said to cause vomiting, so not sure where that note about eating them for emergency comes from. Check it out before eating it! Eat at your own risk!

Dave, thank you for the awesome reply! I have saved that information - and am really happy to hear of some good uses for buckthorn, which is the local weed here. Biochar! carving! (eating? I heard the berries were used to aid vomiting. will re-think.) hooray! thanks. and thanks for all the good thoughts about cold climate and trees.

Shodo,

Actually, I think you are correct re: the berries. It is named "Rhamnus cathartica" after all, and probably for a reason. The database we've pulled together for the coppice book has that note about its use **as an emergency food only**. So I think I will have to do some more research on that myself. Please, whoever reads this, don't eat it without doing your own research first!

d